Candidate: The candidate is an Exercise Physiologist who's initial research focused the Insulin Resistance Syndrome and exercise in African American (AA) hypertensives. The independence and complexity of the candidate's research has progressed during h s postdoctoral training and first 2+ yrs as an Assistant Professor. The candidate is uniquely qualified to pursue an independent research career ingene-exercise interaction in older AA. Research: Hypertension-related morbidity and mortality are devastating in the AA population. Polymorphic variations at many gene loci interact with environmental factors to affect BP. The candidate's preliminary data suggest that endothelial nitric oxide (eNOS) genotype l affects blood pressure (BP), renal hemodynamic, and peripheral vascular responses to exercise training. Thus, our Hypothesis is that common eNOS gene polymorphisms will identify middle-aged to older AA hypertensives who will improve their BP, renal hemodynamics, and peripheral vascular function the most with arobic exercise training. Knowledge of genetically determined exercise training responses in hypertensive AA will result in a more effective HTN treatment. Sedentary hypertensive AA men and women 50-70 yrs of age will be screened prospectively into groups based on their eNOS genotype. Subjects will complete a Dietary Stabilization period and then undergo Baseline Testing of renal hemodynamics, brachial artery ultrasound studies, and 24-hr ambulatory BP and urine collection, followed by 6 months of exercise training and Final Testing. Environment: Receipt of this KO1 and the mentoring of Drs. Hagberg, Ferrell and Weir, will allow the candidate to launch a career in gene-exercise interactions in older AA with hypertension. Dr. James Hagberg has expertise in administering exercise-training interventions in older individuals with cardiovascular disease and in gene-exercise interactions. Dr. Matthew Weir has expertise in assessing renal hemodynamics in hypertensive AA. Dr. Robert Ferrell is an expert in the role of genes in hypertension and other chronic diseases. The candidate will learn and work in a rich research training environment with resources for advanced training and gain the requisite skills and training to embark on independent research career this cutting-edge area of research.